The present invention relates to a multi layered wound dressing and particularly, but not exclusively, to a wound dressing with a high fluid handling capacity for use as a dressing for highly exudating wounds.
It is known to make wound dressings for use on heavily exudating wounds from materials with a high moisture vapour transmission rate (MVTR). Such dressings manage exudate by relying on the exudate being taken up by one side of the dressing and transpired through the other side of the dressing. The dressing itself is thus not required to retain large volumes of exudate,
Examples of such dressings are ALLEVYN™ marketed in adhesive and non-adhesive versions by Smith and Nephew or TIELLE PLUS™ marketed by Johnson and Johnson. Such dressings are not designed to absorb and retain the exudate but to manage the exudate by allowing the moisture present in the exudate to evaporate.
A dressing said to have a high rate of moisture evaporation is described in EP 304 536A. The dressing disclosed in this document has a flexible hydrophilic layer which absorbs the exudate, sandwiched between two layers of adhesive. The absorbent layer additionally contains a fabric layer which is intended to improve the structural integrity of the dressing once it is exposed to exudate. A disadvantage of such dressings is that the lateral wicking of exudate is not contained and can cause the ‘normal’ skin surrounding the wound to macerate.
A further disadvantage of such dressings with a high MVTR is that the rapid loss of exudate can cause the wound to become desiccated.
A further disadvantage of known dressings, in particular foam dressings such as ALLEVYN™, is that if pressure is applied to the dressing in use, such as under a compression bandage system, then exudate absorbed by the dressing is often squeezed out of the dressing. Furthermore, the ability of the dressing to absorb exudate is reduced once compression is applied. Such dressings are thus not suitable for use on wounds where compression is required or experienced.
There is thus a need for a wound dressing which is capable of handling high levels of fluid exudate, for example at least 6 g of exudate per 10 cm2 of dressing in 24 hours, which also does not cause appreciable maceration of the skin surrounding the wound, does not allow the wound to become desiccated, and which can be used, if necessary, under compression.